Because if it is, that is a really sad thing.
Enemy casters run up to melee range, act stupid for a few moments, and (if they are still alive), turn around and fire spells away from thier attackers.
It's the sorriest AI of any MMO I've ever seen. If it were fixed, it would go a long way toward re-balancing player vs. environment. It would go a long way toward making the game challenging and fun again.
I'm begging here. I want to be excited to play. Give me a reason to hope. If there is no plan to fix enemy caster AI, there's no reason to stay.